1. Field of the Invention
This invention relates to low-hazard solid rocket propellant formulations which use little or no chlorine-containing oxidizers. More specifically, the present invention relates to propellant formulations based on a dinitramide salt oxidizer and an energetic binder.
2. Technology Background
Solid propellants are used extensively in the aerospace industry and are a preferred method of powering most missiles and rockets for military, commercial, and space applications. Solid rocket motor propellants have become widely accepted because they are relatively simple to manufacture and use, and because they have excellent performance characteristics.
Typical solid rocket motor propellants are formulated using an oxidizing agent, a fuel, and a binder. At times, the binder and the fuel may be the same. In addition to the basic components, it is conventional to add various bonding agents, plasticizers, curing agents, cure catalysts, and other similar materials which aid in the processing or curing of the propellant or contribute to mechanical properties improvements of the cured propellant. A significant body of technology has developed related solely to the processing and curing of solid propellants.
Many types of propellants used in the industry use ammonium perchlorate (AP) as the oxidizer. AP has been a preferred oxidizer because of its high energy with relatively low associated hazards, its ability to efficiently oxidize the commonly-used aluminum fuel, and its burn rate tailorability. However, there is some interest in the industry to identify alternative oxidizers having similar attractive properties which do not produce chlorine-containing exhaust products.
A commonly used low-hazard nonchlorine oxidizer is ammonium nitrate (AN). This oxidizer has also been examined in many types of propellants. Unfortunately, AN is well known for its poor performance capability, its inability to combust aluminum efficiently, and its low propellant burn rates. These problems continue to plague nonchlorine propellant development efforts.
Accordingly, it would be a significant advancement in the art to provide propellant formulations of equivalent or improved energy capable combusting aluminum efficiently, providing high propellant burn rates, and producing little or no HCl exhaust emissions.
Such propellant formulations are disclosed and claimed herein.